A total of 17 people from EFL clubs have tested positive for coronavirus in the latest round of testing.
There were 10 positive tests returned from eight clubs in the Championship and seven positives from three clubs in League Two. There is no programme of testing for League One at present.
Preston confirmed their player Jayden Stockley was one of the positive tests in the Championship. The striker, who joined from Exeter in January last year, is asymptomatic and says he feels fine.
He said: "I feel absolutely well. I haven't shown any symptoms. I feel great. This has given it a sense of realism for me. I'm the first person I know who has had it. It's a strange feeling, but I'm well and want everyone to take care."
Middlesbrough confirmed one positive test - although they did not specify if the individual in question was a player or a member of their non-playing staff - while Cardiff announced that a member of their staff had also tested positive.
Fulham said one of their players had tested positive. The club announced two positive tests on Thursday.
Colchester had four of the seven positive cases in League Two. Exeter announced two positive tests, while Northampton said physiotherapist Ignacio Herrando had also tested positive.
A total of 1,058 players and club staff were tested in the Championship, while four clubs and 135 individuals participated in the fourth tier.
An EFL statement read: "Those players or club staff who have tested positive will now self-isolate in line with the guidelines provided by the EFL and only those who have tested negative will be permitted to enter training ground facilities.
"The EFL will continue to make regular and relevant announcements as appropriate in respect of the testing programme to support competition integrity and transparency. No specific details as to clubs or individuals will be provided by the League."
The EFL outlined last week it would adopt a "flexible approach" in its finalised Return to Training Protocols (RTT), including the option for players to self-test for coronavirus.
Players and staff will be required to complete a daily medical questionnaire submitted before arrival at the training ground on training days, with access denied if this is not submitted before arrival.
Championship clubs have unanimously agreed to try to complete the season, while League Two clubs are in favour of curtailing the campaign. Clubs in League One (third tier) have so far failed to reach an agreement on how to end the season.
There have been no positive tests for coronavirus after the fourth round of Premier League testing.
The latest batch of tests, which were conducted on Thursday and Friday this week, are the first to take place since clubs unanimously agreed a return to contact training.
A statement read: "The Premier League can today confirm that on Thursday 28 May and Friday 29 May, 1130 players and club staff were tested for Covid-19. Of these, zero have tested positive."
The current testing round was the largest yet, with each club's maximum allocation upped from 50 to 60, and also the first to take place since the unanimous vote to begin contact training.
The previous three rounds, completed between May 17 and May 26, yielded a total of 12 positives from a sample size in excess of 2,700.
There were six positive cases from three clubs in round one, two from two clubs in round two and four from two clubs in round three. Testing will continue on a twice-weekly basis